Analyte monitoring using one or more accelerometers
View Patent ↗The present disclosure relates to methods, devices, and systems for measuring a blood analyte, such as glucose. The disclosure relates more specifically to the use in such methods, devices, and systems of one or more accelerometers to aid in the collection of data, operation of the device, filtering, and other uses. In some embodiments, the accelerometers are three-dimensional accelerometers. An accelerometer can be used in conjunction with analyte monitoring that may be performed with infrared, near infrared, or other wavelength spectroscopy. The accelerometer may allow a monitoring instrument to expect noisy measurement data, indicate positioning of a measurement site for improved expected results, indicate position of the instrument, or help the user properly place or control the instrument. It may also improve analyte monitoring by providing motion information that can be used to help determine and reduce or remove movement-related signal artifacts or noise that may be present within the monitoring signal.
1. A physiological monitoring system including an optical sensor configured to be applied to a finger of a patient, the monitoring system comprising:
said optical sensor including (i) a housing configured to position sensor components proximate tissue of a measurement site on said finger, (ii) at least one accelerometer outputting position signals usable by a patient monitor to estimate a position of the sensor with respect to the patient to provide feedback to the user through a user interface of said patient monitor on how to properly position the sensor with respect to the patient to improve measurement accuracy, (iii) at least one light source, (iv) and at least one photodetector configured to detect light from said light source after attenuation by said tissue of said measurement site of said patient and output physiological signals usable by the patient monitor to determine measurements of one or more physiological characteristics of the patient; and
said patient monitor configured to receive said position signals and said physiological signals over a plurality of monitoring cycles, said patient monitor comprising one or more hardware processors configured to process said position signals continuously and automatically over the plurality of monitoring cycles to estimate said position of the optical sensor with respect to level and with respect to the patient's heart, determine from the estimated position when the optical sensor is positioned above the patient's heart and more than 30 degrees from level, and provide said feedback to said user to reorient said finger based on said determination during the plurality of monitoring cycles, said monitor also configured to process said physiological signals to determine said measurements,
wherein said monitor includes a display and said monitor configured to provide said feedback includes being configured to output indicia to said display responsive to said sensor's position to guide a caregiver or said patient on repositioning said sensor within 30 degrees from level and below the patient's heart with respect to the patient to improve said accuracy of said measurements.
2. The physiological monitoring system of claim 1 , wherein said optical sensor comprises a tissue shaper.
3. The physiological monitoring system of claim 1 , wherein the optical sensor comprises a memory and light source drivers.
4. The physiological monitoring system of claim 1 , wherein said indicia comprises an indication to the patient to reposition said sensor below heart of said patient.
5. The physiological monitoring system of claim 1 , wherein said indicia comprises an indication to the patient to reposition said sensor to level to improve said accuracy of said measurements.
6. The physiological monitoring system of claim 1 , wherein said with respect to level comprises within 10 degrees from level.
7. The physiological monitoring system of claim 1 , wherein said with respect to level comprises within 5 degrees from level.
8. The physiological monitoring system of claim 1 , wherein said indicia comprises graphical information.
9. A method of properly positioning a noninvasive optical sensor with respect to a heart of a patient to improve an accuracy of measurement values determined by processing signals from said optical sensor, the method comprising:
receiving position signals over a plurality of monitoring cycles from one or more accelerometers housed proximate said optical sensor;
receiving physiological signals over the plurality of monitoring cycles from at least one detector configured to detect light attenuated by a tissue of a finger of said patient;
processing said position signals to estimate a position of the optical sensor with respect to level and with respect to the patient's heart;
determining automatically and continuously over the plurality of monitoring cycles using one or more hardware processors, from the estimated position when the optical sensor is positioned above the patient's heart;
determining automatically and continuously over the plurality of monitoring cycles using one or more hardware processors, from the estimated position when the optical sensor is positioned more than 30 degrees from level;
providing a feedback to said user to reorient said finger based on said determination that the estimated position of the optical sensor is above the patient's heart and said determination that the estimated position of the optical sensor is more than 30 degrees from level;
processing said physiological signals to determine measurements of one or more physiological characteristics of the patient, wherein said providing said feedback includes outputting indicia to a display responsive to said sensor's position to guide a caregiver or said patient on repositioning said sensor within 30 degrees from level and below the patient's heart with respect to the patient to improve said accuracy of said measurement values.
10. The method of claim 9 , wherein said indicia comprises an indication to the patient to reposition said sensor to level to improve said accuracy of said measurement values.
11. The method of claim 9 , wherein said with respect to level comprises within 10 degrees from level.
12. The method of claim 9 , wherein said with respect to level comprises within 5 degrees from level.
13. The method of claim 9 , wherein said providing said indicia comprises a graphical information.